Texin — Precision Pen Case Injection Molding Product for Reliable, Attractive Pens

Texin manufactures high-quality pen case injection molding product (pen housings and barrels) designed for the demanding needs of stationery brands. Pen cases look simple but require tight straightness, uniform wall thickness (typical ~1 mm), consistent color and finish, and high-volume cost control. Because pen barrels are long, hollow parts with a small end hole, they present specific cooling and balance challenges. Texin combines practical DFM, experienced tooling and precision production to deliver pen cases that meet appearance, fit and functional expectations in high-volume runs.

Why pen case injection molding product needs careful engineering

• Long hollow geometry: center cores cool slowly, so cooling design and cycle optimization are critical to avoid warp and straightness issues.
• High cavity, high volume: many pen molds run 16–72 cavities to reduce unit cost — that requires careful flow balancing and valve/gate strategies.
• Color variety: hundreds of colors are common; changeover waste and color-matching procedures must be controlled.
• Functional tolerances: snap-fit caps, internal ribs and ink-carrier fits need repeatable tolerances and consistent part weight.

What Texin delivers (practical, measurable)

• End-to-end process: feasibility (1–3 days) → mold design (3–7 days) → materials procurement → precision CNC/EDM machining → assembly & debug → trial molding & optimization.
• Material & tooling options: common tool steels (45# for prototypes, 718H for mid runs, S136 for mirror finishes, NAK80 for high-precision cavities). Domestic steels usually available in 1–3 days; imported mirror steels 1–4 weeks. Material typically 20–30% of mold cost; machining and processing often 30–50% of cost and 40–60% of lead time.
• Pen-specific tooling expertise: hot-runner with valve gates to reduce drool and shorten cycles, optimized gate locations for long barrels, conformal cooling or enhanced core cooling options to cut cycle time and improve straightness.
• Precision and inspection: CNC machining + EDM finishing for cavities, CMM & Ra checks, first-article reports (FAR). Typical achievable tolerances for critical small features: ±0.01–0.005 mm. Trial runs normally 1–3 days; 2–3 iterations common for function tuning.
• Production support: color-change SOPs, balanced multi-cavity tooling, and automation options (pick-and-place, stacking) to reduce labor and scrap.

Common buyer & producer questions — concise answers with data Q: What files do you need to start?
A: Please provide 3D model (STEP/IGES/Parasolid) + 2D key-dimension drawings, material choice (e.g., PP/ABS/PC), surface finish target, and expected annual volume. This enables a 1–3 day feasibility review.

Q: What steels & mold life do you recommend?
A: For prototyping use 45#; for standard production use pre-hardened 718H; for glossy/mirror finishes choose S136; NAK80 for fine cavities without heavy heat treatment. Material choice balances finish and lifetime — mirror steels cost more but are suited to long cosmetic runs.

Q: How do you solve the cooling problem for long pen barrels?
A: We optimize cooling with deeper core channels, dedicated internal cooling or conformal cooling where justified. We also use balanced gating, hot-runner valve gates, and trial tuning to minimize warpage and achieve straightness.

Q: What about cycle time and cavity count?
A: Many pen projects use high-cavity molds (16–72) to lower unit cost. Machining/processing usually consumes 40–60% of lead time; investing in balanced runners and valve gates helps keep cycles short while protecting quality.

Q: How do you handle many colors and fast changeovers?
A: We recommend color-grouped production runs, strict purge/clean protocols and dedicated color-change SOPs. For high-mix customers we can design quick-clean hot runners and offer automated changeover/cleaning support.

Q: What quality documentation is provided?
A: FAR (first article report), CMM reports for critical dims, surface roughness (Ra) checks, material certificates (MSDS) and trial-shot photos. Standard export paperwork (RoHS, ISO-related docs) available on request.

Practical tips for a successful pen case program

• Confirm critical straightness/weight tolerances at project start (we recommend specifying part weight and permissible +/- tolerance, e.g., ±0.5% or ±0.1 g for small parts).
• Provide target surface finish sample (gloss/matte/texture) early so cavity texturing/polishing can be planned.
• If volumes are high, consider investing in valve-gate hot runners and improved cooling — higher upfront mold cost reduces per-part cost and shortens cycle later.

Summary：

A robust Pen case injection molding product program demands focused DFM, correct steel selection (45#, 718H, S136, NAK80), precision CNC/EDM finishing, optimized cooling and balanced multi-cavity design. Texin’s six-stage workflow, trial-driven tuning and production support (color SOPs, FAR, CMM) deliver pen housings that look right, fit right and run reliably at scale. To start, send your 3D files, 2D key dims, material and volume — Texin will return a feasibility review, realistic timeline and tailored plan for your pen case injection molding product.

Ready to discuss your pen case project? Send files to Texin and get a feasibility review in 1–3 days.

● Many years of mold design, development and manufacturing experience

● Pursue excellence and cast high quality

● High quality, high efficiency and high precision

● Take the initiative to provide timely, fast and dynamic customer service